MON-063 Managing a Resistant GH-Secreting Adenoma: A Case Report Highlighting Barriers to Patient Care

Abstract Disclosure: L. De Mattei: None. B. Celik: None. M. Kashat: None. M.Q. Morato: None. A. Banka: None. Background: Acromegaly is a progressive disease mainly caused by excess production of GH and insulin-like growth factor (IGF)-I from a pituitary adenoma. Resistance to treatment is frequent in clinical practice; thus, a multimodal approach is essential to avoid disease progression and increased mortality. Case: A 59-year-old Arabic-speaking female with acromegaly and diabetes was referred to our Endocrine office in 2020. An Arabic interpreter assisted communication. In 2010, she had an invasive adenoma with focal prolactin and GH immunoreactivity removed at another hospital and no labs were available. Post-surgery, Octreotide and Pasireotide were ineffective, the latter discontinued due to hyperglycemia. Brain MRI in 2018 had shown a 0.8 x 1.1 x 1.3 cm pituitary mass. Laboratory workup in our clinic showed A1C 11%, IGF-1 383 ng/mL, GH 1.9 ng/mL, free T4 0.71 ng/dL, morning cortisol 12.5 ug/dL, prolactin 1 ng/mL. Insulin, Cabergolin, and Lanreotide were prescribed, but she took inconsistently. Later, addition of Pegvisumat was also unsuccessful. Her care was fragmented given infrequent follow-ups and low health literacy. At first, she adamantly refused radiation or surgery but given persistently high levels of IGF (409), increased tumor size (MRI 2023 showed 1.1 x 1.4 x 1.5 cm mass), headaches, and facial/acral changes, she ultimately agreed to radiation. After 30 sessions, MRI (2024) showed stable mass, A1C 8.5%, but IGF-1 remained high at 339 prompting Lanreotide re-initiation. She has been more consistent with follow-ups and medication adherence. Discussion: The treatment of acromegaly aims to normalize GH and IGF-1 levels, stabilize pituitary mass, and manage complications, including cardiopulmonary, osteopathic, oncologic, and glucometabolic issues. The standard of care involves transsphenoidal surgery combined with medical therapy and occasionally radiation, however, resistance to treatment is common. First-generation somatostatin receptor ligands (SRLs) like Octreotide and Lanreotide effectively control GH levels and tumor growth, although chronic injections pose a high risk of noncompliance. Second-generation SRLs, such as Pasireotide, achieve greater tumor shrinkage but often induce hyperglycemia, particularly in diabetic patients. In such cases, Pegvisomant, a GH antagonist, is preferred, though it has no impact on tumor size. When radiation is required, biochemical control may take years, so medical therapy is usually restarted. Frequent follow-up is essential for patients with resistant disease to assess the need for alternative or adjunctive therapies. Our patient highlights the impact of low health literacy and language barriers on treatment adherence and outcomes. Physicians must adopt a patient-centered approach that includes clear communication, culturally sensitive education, and the involvement of interpreters or community resources as needed. Presentation: Monday, July 14, 2025